| 摘要 |
<p>A water vapor-permeable, air-impermeable and water-impermeable sheet material comprises a film bonded to a fibrous substrate. The film comprises a reaction extrusion-processed blend comprising a first block copolymer which comprises a polyether block amide copolymer and a second block copolymer which comprises a copolyether ester. The fibrous substrate may be woven or non-woven, and may comprise polyethylene, polypropylene, polyethylene terephthalate, a polyamide, glass mat, felt, paper, or combinations thereof. The water vapor transmission rate of the extruded film is substantially higher than that of a film made from either one of the component block copolymers. The sheet material has uses which include housewrap, roofing underlayment, breathable apparel, desiccant packaging and others.</p> |
